Method and assembly for transferring space modules

ABSTRACT

A prefabricated space module resting on a horizontal support surface is transferred using at least three elongate stands, each stand having a wheel at a first end and an engagement element at a second end. The engagement elements are adapted to engage respective attachment elements of the space module. Each stand is of a length such that a surface region of the wheel at the first end of the stand can engage the horizontal support surface when the stand is inclined to vertical and the engagement element at the second end of the stand is engaged with an attachment element of the space module. By displacing the first end of each stand toward a position in which the stand is more nearly vertical while the engagement elements remain engaged with the respective attachment elements, the space module is elevated clear of the horizontal support surface.

BACKGROUND OF THE INVENTION

The present invention relates to a method for transferring prefabricatedship cabin modules and similar components in ships, offshore structuresand buildings erected on land.

The invention also concerns an assembly for transferring a space module.

Increasingly it is desired that structures of ships, offshore drillingplatforms and similar constructions be first assembled intoprefabricated components which are then mounted in place to the ship'sbase structure on-site at the shipyard. This approach offers anessential time reduction in the erection schedule and cost cutting,because a major part of the structures can be prefabricated industriallyon efficient manufacturing lines. Particularly cabin structures aretypically pre-fabricated into fully furnished modules which aretransferred as complete modules into the ship. Then, the decoration andfurnishing works of the cabin module can be completed in the indoorpremises of assembly halls thus avoiding awkward detail furnishing inthe ship itself. However, prefabricated cabin modules are relativelylarge and their transfer requires different kinds of accessories to aidtheir final positioning. Such transfer operations are complicated by thefact that a semifinished ship does not necessarily have enough room topermit the use of hoists, fork trucks and other transfer equipment.

U.S. Pat. No. 3,363,597 discloses a method of assembling the ship'sinterior spaces from prefabricated space modules. According to thismethod, the interior spaces are assembled from space modules equippedwith support flanges, whereby such modules are designed to includeseveral space units in one module. The interior space modules aremounted in a matrix-like beam lattice in several tiers by inserting themodules in the openings of the lattice and then fixing the modules toeach other. The transfer of such modules is extremely clumsy as they arenot compatible with any conventional transfer equipment.

Patent publication SE 377,681 discloses a container ship in which thecontainer hold may be temporarily converted into a passenger spacecomprised of cabin and/or similar containerized modules. The containersare connected by temporary arrangements to the ship's HPAC andelectrical systems. The assembly of the passenger cabin section takesplace using cabin, shower, stairway and bathroom modules with dimensionscompatible with the ISO standard containers. Most of these units areadapted to have an accessway extending laterally through the unit. Unitsof the same tier are placed in rows so that the accessways form corridorsections, which can be joined from the opposite sides of the samestairway module to provide an access between two superimposed tiers.According to the disclosed arrangement, identical modules in thesuperimposed tiers are suggested to be superimposed above one anotherbetween two decks of the ship. Hatchways with covers are providedbetween the uppermost stairway module and the upper deck. Permanentlyinstalled HPAC and electrical supply systems are placed on the lowermostdeck. The containerized modules are transferred by means of conventionalcontainer handling equipment. Such a system is suited to specialapplications and temporary service only, and is not intended for use inconventional shipbuilding.

FI Pat. No. 62,984 describes a system which is based on the use ofprefabricated, floorless cabin modules. Except for their lacking floor,such modules are ready-for-use space modules which form a finished,easy-to-mount cabin requiring no major finishing and decoration afterits installation in place. The transfer of the floorless cabin module toits installation site occurs by first mounting detachable wheels to thecorners of the module and then pushing the module from the inside. Inthis manner the modules can be easily transferred even to tight places.The transfer elements which are temporarily connected to the cabinmodules are economical in use, and, e.g., with respect to a permanenttransport carriage, such temporary transfer equipment offers significantcost savings as the temporary transfer elements can recovered for reuse.The wheels to be temporarily adapted or mounted to the corners of thecabin module should preferentially extend horizontally only marginallyoutside the cabin module. Each transport unit is provided with adetachable transfer element and a frame to which the cabin module issupported during the transfer operation. The transfer element, e.g., awheel is supported to the frame of the transport unit at the undersideof its bottom corners and edges.

By arranging the transport units basically to the inside of the cabinmodule, the module is easy to support laterally to the frame of thetransport unit. Then, the transfer elements can be replaced from insidethe cabin unit. A shortcoming of this transfer system is that liftingthe cabin module onto the wheels still requires the use of a separatelift means, which complicates the handling of the cabin module. Wheelsof the above-described type are suitable for the transfer of floorlesscabin modules only, which curtails the applications of this arrangement.Moreover, the cabin module must be rather rigid, because its weight isimposed directly from above onto the fixing elements of the wheels whichare attached to the lower edges of the walls and said fixing elementsare relatively poorly suited to provide support to the cabin module.Hence, the cabin module lower edge must be reinforced to make the moduleedge capable of taking the stresses at the fixing points of the transferelements. The mounting of the space module is further impeded andcomplicated by the fact that the space module must be opened and amechanic has to enter the module in order to mount the transfer elementsin place and to push the module. As it is difficult to guide the modulein place by operating from its inside, several craftsmen are required tohandle the module.

Prior to their transfer and mounting in place, such modular cabins areoutfitted with required furniture and other equipment. This arrangementavoids, e.g., the moving of furniture through the narrow accessways ofthe ship. In fact, furniture and other equipment possess an inherentrigidity in themselves. This property is utilized by mounting the fixedfurniture and other permanent appliances to the walls of the cabinmodule so as to increase thereby the rigidity of cabin modules.

FI Pat. No. 62,984 further mentions that cabin modules can be moved andmounted in place supported by an air cushion. To form and maintain suchan air cushion, the cabin modules are provided at their open bottom witha tight, pouch-like apron unit suited for filling by air feed and havingan exit opening. The pouch-like element which thus supports the cabinmodule is made from a plastic film, for instance. However, such a methodis rather expensive and the large fan required to keep the modulefloating causes severe noise abatement problems in the closed spaces ofa ship.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a method in whichdifferent kinds of space modules can be transferred in an easy andsimple manner without the use of auxiliary lifting equipment.

The object of the invention is accomplished by providing thetransferrable space module with at least three scaffold-stands withwheels, whereby said stands are attached at their distal ends withrespect to the wheels to the outside of the module so that the distancebetween the attachment point and the lower edge of the module is smallerthan the maximum length of the stand from the attachment point to theextreme lower point of the wheel, and then the module is elevated withthe help of the stands to the transfer position.

The invention offers significant benefits.

The most important advantage of the invention is that the assemblyitself can function as the lifting means thus disposing with the needfor any separate lifting equipment. The lifting operation is performedfrom outside the space module, whereby the module need not be opened forlifting. According to the most advantageous embodiment of the invention,the lifting members are attached to the upper edge of the module roof,whereby the module weight is distributed evenly between the roofstructures and the module is prevented from swaying under stressesimposed by its own weight during the transfer operation. Hence, thepresent invention makes it possible to transfer even the most elasticmodules, because the module is supported by the lifting members duringits transfer. Another embodiment of the invention includes a latticefixed above the module so as to further support the module. The liftingand transfer of the module require no large high-power or specialequipment. As the module is advantageously lifted at fixed liftingpoints attached to the module, the same lifting points may also be usedfor other transport operations of the module. The method according tothe invention makes it possible to handle all kinds of space modules nomatter if they have a floor or not. Typical objects to be handled arethe cabin modules of ships and drilling platforms, room modules ofhotels and floating hotels, various machinery spaces including spacesfor lift machinery and similar equipment and other prefabricated spaces.

As the space modules are relatively light weighing typically approx.2000-3000 kg, in a four-stand system the load imposed on each stand isaccordingly rather low permitting a lightweight construction of thestand. Hence, a single mechanic can alone handle the stands and preparethe module for the transfer operation.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is next examined in greater detail with reference toattached drawings, in which:

FIG. 1 illustrates a space module with the transfer members according tothe invention attached thereto;

FIG. 2 illustrates a detail of the diagram of FIG. 1; and

FIG. 3 illustrates an embodiment of the connection between the spacemodule and the transfer members.

DETAILED DESCRIPTION

Now referring to the drawings, the transfer of a single space modulerequires four transfer members or stands 3. Each stand 3 comprises twotelescoping tubular elements 11, 12, a stand length adjusting mechanism9, a wheel mounted on a shaft 6 at the lower end of the stand and afixing stub 2 of hollow square section mounted to the upper end of thestand by means of a shaft 7 as well as an eyelet 5 for a tighteningstrap. Each upper corner of the space module 13 to be transferred isprovided with a hollow square section 8 into which the fixing stub 2 isadapted to fit. In the embodiment illustrated in FIG. 1, the hollowsquare section 8 is extended over the entire length of the long sides ofthe space module 13, whereby the sections 8 provide additional supportto the roof of the module 13. When prepared ready for the transfersetup, the module 13 is surrounded by a tightening strap 1 adapted topass via the eyelets 5. The length adjustment of the stands isimplemented in the exemplifying embodiment illustrated in the drawingsso that the telescoping tubular elements 11 and 12 of the stand areprovided with a series of drilled holes 14 into which a locking pin 15can be inserted. Thus, the length of the stands is readily adjustable bymoving the position of the locking pin 15 in the holes.

According to the invention, the space module 13 is transferred asfollows. During its prefabrication stage, two sides of the module areprovided with a hollow square section 8 extending over the entire lengthof the side. The open ends of these hollow sections 8 form theattachment points for the transfer stands 3. The connection of thestands 3 to the module takes place by inserting the square fixing stub 2into the end of the square hollow section 8. The length of the stands isadjusted such that the length L of the stand from the shaft 7 of thefixing stub to the shaft of the wheel is at least as large as thedistance H of the hollow square section 8 from the lower end of themodule 13. With this height adjustment, the module is elevated by theradius of the wheels 4 of the stands 3 from the ground level. Whenrequired, the stand can be set for a larger length, whereby more spaceremains between the bottom of the module and the transport route.

After the stands 3 are fixed to the upper corners of the module, thetightening strap 1 is passed about the module 13 via the eyelets 5. Atthis stage, the stands 3 are still inclined with respect to the walls ofthe modules 13 at an angle determined by their set length. When thetightening strap 1 is tightened with the help of a tightening device 10,the stands 3 are pivotally rotated about the shaft 7 and thus movedcloser to the walls of the space module 13. Simultaneously, the moduleis elevated from the ground level, and as the module is elevatedsufficiently high from the ground, it can be moved by pushing to thedesired place. The stands can be left either in a slightly tiltedposition or tightened upright against the walls of the module as shownin FIG. 1. Obviously, the loading of the stands remains lower in theupright position.

Besides those elucidated in the foregoing, the invention may havealternative embodiments.

The length adjustment of the stands can be implemented in a plurality ofdifferent manners, for example, by jack screws. Stand constructionsbased on the upper pivotal joint and a simple, stepwise adjustablearrangement of stand length are essentially less complicated toimplement and less costly to manufacture. In fact, the stand lengthadjustment is not absolutely necessary at all if the modules to betransferred have a standard height, or alternatively, if a selection ofstands of different lengths are used. The connection between the spacemodule and the stands may also be implemented in any desired manner.According to an interesting embodiment the module is grabbed by means ofa lattice placed atop the roof of the module. The connection between thelattice and the module may be, e.g., similar to that used to transfercargo containers, whereby the module may be easily moved by means ofcontainer handling equipment. Obviously, the stands may be fixedpermanently to the roof grabbing lattice, while a detachable connectionis preferred due to the easier handling and transport of the separatemembers detached from each other. The roof grabbing lattice isadvantageously made adjustable by its size. All connections can beassured by locking pins, for instance.

When desired, the module can be transferred using three stands only,whereby one of the stands is located at the center of a wall. The wheelsof the stands are advantageously standard industrial wheels or rollers.The tightening means can adeptly be a conventional cargo securing strapwith a tightening mechanism, while other types of tightening devicesoffering easy tightening may also be used. If jack-type stands areemployed, they can be fixed to the walls of the space module with thehelp of locking pins or similar locking means whereby the tighteningstrap is obviated. However, as the encompassing strap providesadditional stiffening of the structure, its use is recommendable.Furthermore, the scope and spirit of the invention entails such atransfer system in which the stands are connected to lower points of themodule walls or corners than to the upper edge of the module roof,whereby such an arrangement subjects the module walls unnecessarystresses during lifting and transfer. The pivotal joint of the standabout which the stand is pivoted during the lifting operation may belocated lower in the stand than at its upper attachment point.Accordingly, the pivotal point may even be close to the center of thestand, but this arrangement necessitates assuring the stability of thestand by suitable locking means.

We claim:
 1. A method for transferring a prefabricated space modulehaving a lower edge resting on a horizontal support surface and alsohaving an exterior surface and at least three attachment elementsexposed at the exterior surface and spaced vertically from the loweredge, said method including:(a) providing at least three stands, eachstand having first and second opposite ends with a wheel at its firstend and a pivoting engagement element at its second end, and wherein therespective engagement elements of the stands are adapted to engage theattachment elements respectively and each stand is of a length such thata surface region of the wheel at the first end of the stand can engagethe horizontal support surface when the stand is inclined to verticaland the engagement element at the second end of the stand is engagedwith an attachment element of the space module, (b) engaging the wheelsof the stands with the horizontal support surface and engaging theengagement elements of the stands with the attachment elementsrespectively, and (c) displacing the first end of each stand toward aposition in which the stand is more nearly vertical while the engagementelements remain engaged with the respective attachment elements, wherebythe lower edge of the space module is elevated clear of the horizontalsupport surface.
 2. A method according to claim 1, wherein the spacemodule has upper corners and the attachment elements are exposed at theupper corners of the space module.
 3. A method according to claim 1,wherein the attachment elements are sockets and the engagement elementsare plugs adapted to fit in the sockets, and step (b) comprises engagingthe plugs with the sockets by horizontal relative movement.
 4. A methodaccording to claim 1, wherein each stand comprises an arm and theengagement element is pivotally attached to the arm, and wherein step(c) comprises pivoting the arm relative to the engagement element.
 5. Amethod according to claim 1, wherein step (c) comprises providing astrap extending around the space module and operatively engaged with thestands, and tightening the strap so as to force each stand to asubstantially vertical orientation and simultaneously secure the standsto the space module.
 6. A method according to claim 1, wherein theprefabricated space module is substantially rectangular in plan and hasfour upper corners at which respective attachment elements are exposedat the exterior surface of the module, step (a) comprises providing fourstands and step (b) comprises engaging the engagement elements of thefour stands with the four attachment elements respectively.
 7. Anassembly for transferring a space module having a lower edge resting ona horizontal support surface and also having an exterior surface and atleast three attachment elements exposed at the exterior surface andspaced vertically from the lower edge, said assembly including:at leastthree stands, each stand comprising an elongate arm with first andsecond opposite ends, a wheel attached to the arm at its first end andan engagement element pivotally attached to the arm at its second end,and wherein the respective engagement elements of the stands are adaptedto engage the attachment elements respectively, and each arm is of alength such that a surface region of the wheel at the first end of thearm can engage the horizontal support surface when the stand is inclinedto vertical and the engagement element at the second end of the arm isengaged with an attachment element of the space module, and adisplacement means coupled to the stands for displacing the first end ofeach arm from an inclined position toward said space module to aposition in which the arm is more nearly vertical, by pivoting the armrelative to the engagement element, while the engagement elements remainengaged with the respective attachment elements, whereby the lower edgeof the space module is elevated clear of the horizontal support surface.8. An assembly according to claim 7, wherein the displacement mechanismis a strap surrounding the space module and in operative engagement withthe stands and a tightener for tightening the strap and forcing thestands toward a vertical orientation and simultaneously securing thestands to the space module.
 9. An assembly according to claim 7, whereinthe arms are adjustable in length.
 10. An assembly according to claim 9,wherein each arm comprises a first tubular member formed with at leastone hole, a second tubular member in telescoping engagement with thefirst tubular member and formed with at least two holes, and a lockingpin threaded through aligned holes in the tubular members.